1. The Field of the Invention
The present invention relates generally to multimedia communication networks. More particularly, embodiments of the present invention relate to an improved Voice over Internet Protocol (VoIP) network that provides for increased data stream throughput for video/voice/data via a private Internet Protocol (IP) communications network with associated communications components.
2. Description of Related Art
To understand the need for the improved design of the present invention requires a brief overview of the current solutions that need to be replaced, the available technology, and the areas of anticipated future growth. As none of the existing VoIP standards support all necessary telephony signals and messages, vendors develop special proprietary messages and controls to allow important features. Therefore, the current market products do not interact at the capacity required to offer carriers separate high performance, scalable, and reliable building blocks to build viable nationwide VoIP networks.
The public switched telephone network (PSTN) was built over many decades to accommodate basic telephony communications. As a result, other types of signals, such as data, video, and fax are presently formatted inefficiently to fit into the framework of the voice structure in the PSTN network. Presently, the telecommunication industry is undergoing a dramatic reorganization and reconnection. As newer technologies mature and develop, their deployment base, cost, and reliability approach the necessary size, expense, and dependability levels required to replace the old public switch technology. There is also a significant amount of engineering effort directed towards the selection of elements and components built for the PSTN that could be reused by a telephone network successor. Despite these changes, the infrastructure of the standard publicly switched telephone network (PSTN) has remained virtually the same. What is needed is a protocol and architecture that allows simple interfacing between new and legacy components.
The legacy PSTN supplies reliable and simple voice communication via an analog data transmission medium, but is not well suited for modern digital communication. While the public infrastructure actually consists of many different networks and technologies, much of the system can be characterized as having two inherent shortcomings. First, the reserved bandwidth in most voice calls is idle for much of the call duration, yet it is unavailable to carry other traffic, creating a systemic inefficiency. Second, the only intelligence in the system is found in the carrier's routing and control logic resident in the switches and control network. Basically analog local loops are connected to a local class five switch, which connects to other backbone and local switches through two separate networks. One network of inter-machine trunks carries the actual media traffic in the form of 64 kbs time division multiplexed (TDM) streams. A separate packet switched network carries call signaling, and control instructions using the SS7 protocol. As such, much of the logic for call connection and routing is resident in the switches, but additional logic for services, such as 800 number services, is drawn from Service Control Point databases on the SS7 network. When a call is placed on this network, instructions sent over the control layer allocate physical resources (ports and bandwidth) in the transport layer, creating a private channel of fixed bandwidth that is maintained for the duration of the call. In essence, this is a system that is highly adapted to a limited, historic set of functions, and which is not readily adaptable to new types of services or a wider range of media inputs. What is needed is a distributed architecture that allows data to be transmitted via a variety of message types optimized for the data being sent and for the network being used.
In contrast to the PSTN, the Internet supplies reliable and rapid computer data transmission without the added burden of long-distance charges. Originally developed by the government to facilitate communication in adverse conditions, the DARPA project consisted of a computer network that did not rely on any single node or cable for its existence. DARPA was specifically developed to provide multiple pathways for communication to flow from a source to a destination. Data can thus be routed along a large variety of pathways, successful transmission is not dependent on anyone single pathway for a majority of the message to be successfully delivered. The successor to the DARPA project is the popular and widely used Internet. Transmission of analog or voice data via the Internet is viable because voice data can be digitized and the Internet is a global transmission medium, which substantially duplicates the area covered by the PSTN. An even greater advantage is the fact that Internet access generally includes all data transmission fees in the base cost unlike the PSTN were the base cost only includes connectivity and the user pays additional fees for data transmission, such as long distance calls. Presently available PSTN systems cannot supply high connectivity without adding unreasonable restrictions. Such systems should also supply support for multi-media and variable message types. What is needed is a protocol and architecture that takes advantage of the Internet's high connectivity, natural command and control infrastructure, multimedia support, and uses low cost and low complexity internet-scalable devices.
The standards organizations do not keep pace with modern technological developments, due in part to the fact that the standards organizations are very political and the increasing speed at which products are developed in the “Internet economy”. Generally a selected protocol tends to give technological preference to one vendor over another, so the various vendors participating in the standards committees are naturally at odds with proposals presented by other vendors. This slows the progress, development, and the performance of the standards eventually implemented. What is needed is a truly efficient, interoperable and carrier grade protocol for use over a packetized network. The standards organizations, in general, and the VoIP market, in particular, are fragmented with many different protocols that compete and overlap. Presently, the two major VoIP protocols competing in the carrier market space are H.323 and SIP.
Developed originally for the transfer of multi-media signals over non-reliable networks (such as LAN), H.323 has been transformed in an attempt to meet the needs of a true carrier grade network. Although it is an approved standard by the International Telecommunication Union (ITU), the H.323 protocol faces significant opposition in the market due to its high complexity and lack of complete carrier grade support. In theory, H.323 should enable users to participate in the same conference even though they are using different videoconferencing applications. But it's too early to say whether such adherence will actually result in interoperability, even though most videoconferencing vendors have announced that their products will conform to H.323. What is needed is a packetized communication protocol that provides carrier grade support through simple compatible building blocks.
A much simpler and modern protocol, SIP places special emphasis on SS7 support. As the SIP protocol is still secondary in the industry to H.323 in terms of deployment and support by vendors, the future of the SIP protocol is unclear. What is needed is a communication protocol that supplies an open interface to existing and emerging standards, such as SS7 and H.323.
As attention to VoIP rises, there is an increasing collection of vendors in the market. Many of these vendors have developed products that work well in labs or small-scale installations; however, they are completely unsuitable for a carrier grade network requiring a call capacity of many millions of calls per hour. Obtaining carrier grade performance should be one of the driving forces in the design of any new network component or network architecture. What is needed is a network architecture that designs each component, which could cause a bottleneck, as a distributed application, thereby enabling replication of the resource to enhance overall network capacity.